Eco-Friendly Cloud Point Extraction Coupled With a Spectrophotometric Method for the Determination of Ranitidine Hydrochloride in Pharmaceutical Samples

Abstract

The simple, rapid, economical, and environmentally friendly method was developed for spectrophotometric determination of ranitidine hydrochloride (R-HCl) in pharmaceutical samples after extraction by the cloud point method. The method based on the reduction of Fe(III) by ranitidine hydrochloride to Fe(II), which subsequently reacted with ferricyanide to form colored products at (pH 4.0), then Triton X–114 surfactant was used as an extractant for ranitidine hydrochloride. The linearity of the calibration curve was maintained from concentrations between 0.5–60.0 μg/mL at the maximum absorption 693 nm. Factors required for reaction conditions including pH, FeCl3, and K3[Fe(CN)6] concentration, the volume of surfactant, temperature, time, and order of addition were investigated. Regression analysis indicates that the correlation coefficient was 0.9998 and the molar absorptivity was 0.46x104 L/mol.cm. Detection and quantification limits were 0.475 and 1.567 μg/mL, respectively. The confidence limit of slope and the confidence limit of the intercept at 95% were 0.0147 ± 0.00015 and 0.0642 ± 0.01033. Sandell`s sensitivity was also calculated and it was found 0.0680 μg/cm2. The preconcentration factor was 50.0%. Validation studies for three different concentrations (5.0, 10.0 and 30.0) μg/mL of ranitidine hydrochloride gave relative standard deviations between 0.142–0.728 and the percentage recoveries ranged from 98.780 ± 0.719 – 99.840 ± 0.142. The proposed method was successfully applied for the determination of ranitidine hydrochloride in some of its pharmaceutical products with recovery between 99.108–99.808 and RSD% between 0.012–0.031. The results obtained from the proposed method make it suitable to use in the determination of ranitidine hydrochloride in its bulk and tablet dosage form.